Project Summary/Abstract The missions of the American Society for Photobiology (ASP) are to promote original research in photobiology, facilitate the integration of different disciplines in the study of photobiology, promote the dissemination of knowledge of photobiology, and provide information on the photobiological aspects of national and international problems. The ASP is hosting the 40th Biennial international meeting to be held in the handicap- accessible Sheraton Grand Chicago hotel, in Chicago, IL, from June 27 ? 30, 2020. ASP meetings are multidisciplinary and have typically attracted ~200 participants worldwide. The ASP promotes research in photobiology in all disciplines. Photobiology is a broad field composed of multiple disciplines, including but not limited to photophysics, photochemistry, photobiology, phototoxicity, phototechnology, and photomedicine. The scientific discoveries in photobiology have provided new opportunities to develop (i) approaches to protect humans and other organisms from photodamage, (ii) strategies to utilize the beneficial effect of light, including but not limited to photomedicine, and (iii) new tools for biological and biomedical research, including epigenomics, epitranscriptomics, imaging, diagnosis, and targeted therapy. Recently these meetings have been held every two years. Particular emphasis has been placed on disseminating scientific discoveries, fostering collaboration, and promoting the careers of young investigators. The ASP meetings serve as a pivotal constructive forum for scientists at all career stages, for those already in the field as well as for those contemplating a career in photobiology. Attending the ASP meetings gives scientists the unique opportunity to meet other photobiologists from diverse disciplines for scientific exchange and in-person interaction with their fellow photobiologists. Those interactions are not only critical for fostering creative ideas and collaboration, but also pivotal for training young investigators with the dedicated programs centered on mentoring young investigators.